Competition policy authorities in the EU are on the warpath against US tech giants such as Facebook, Amazon, Apple, Netflex, and Google, collectively referred to as the FAANGs. Hardly a week goes by without pronouncements from the continent that the FAANGs reduce competition and thus imposing penalties on them is warranted.

It is less clear, however, if this toughened position is rooted in rigorous empirical assessments that demonstrate such firms have exacted market power on EU consumers, resulting in excess profits, or, whether instead it stems from envy that the EU hasn’t created its own Silicon Valley. Similar battles are being waged on many of the same high-tech firms in locales less advanced than the EU economies, particularly large emerging markets like India.

Yet, there the argument is largely that these firms create barriers to entry by local start-ups.

Among us veteran practitioners in antitrust economics and who also happen to live in the US — the very first place any market dislocations would likely emerge from untoward business practices by such firms — there is largely a consensus that rendering conclusive judgements about whether the public interest has been advanced or harmed by these companies is not a cut and dried matter.

Here are some reasons why.

With few exceptions, there is broad agreement the omnipresence of the FAANGs means that high-tech industries in the US, whether defined in product or geographic terms, have become more concentrated. That is, the number and size distribution of US technology firms selling a particular set of goods and services — or purchasing certain inputs, including the hiring of specific types of workers — have decreased.

Amazon’s e-commerce business — which initially only sold books — is the most visible example of increased dominance in the digital retail sales space, an industry that for all intents and purposes didn’t exist before 1990. It has genuinely revolutionised shopping in that short time frame. From a computer anywhere in the world one can buy virtually any retail item without having to go to a store; view instantly data on other customers’ reviews of the item; and after charging the purchase on a credit card, the item will be delivered within days (with nominal or sometimes free shipping); and returning items is just as easy.

The time and cost efficiencies of shopping on Amazon is nothing short of astounding. Nevertheless, many Americans bemoan the rapid growth of Amazon’s business model has meant the disappearance of local, small shops from which to buy consumer goods. Yet other large players in the retail sales sector — far more established than Amazon, such as Walmart and Target — have also increased their market footprints substantially. But they have done so largely on a brick-and-mortar basis. In so doing, they, perhaps like Amazon, have edged out small retail proprietors.

Moreover, Walmart and Target have begun to adopt an aggressive e-commerce strategy to try to compete head to head with Amazon. In short, they’ve adopted the ingenuity of Jeff Bezos’ business model.

Similarly, Amazon has expanded and matured, it’s realised that its Seattle-based brick-and-mortar centralised system of control is no longer optimal. The company is now in the throes of building a second hub on the US East Coast. More ironically, in certain cities, Amazon has begun to put up its own brick-and-mortar bookstores!

It would be premature to suggest that a fundamental convergence between Amazon, Walmart and Target is underway. Yet, it is clear that, at least in this industry, market dynamics are robust, competition is thriving, and innovation is hardly the province of one firm. Still, Amazon’s secret sauce of e-commerce has positioned it to be by far the biggest player in the retail market — by a long shot.

Among the rest of the FAANGs, one sees similar patterns. Hence why they have become a focus of the antitrust authorities.

However, from an antitrust perspective, the key question is not simply whether a market is concentrated. Rather, it is whether as result of such dominance, do firms operating in such markets charge prices in excess of their costs, earning margins higher than what otherwise would be the case if there were more firms in the market, and erect entry barriers, through a variety of behaviours, that prevent potential rivals from operating successfully in the market and compete down those higher margins?

The answer tends to boil down to what drove the increased concentration. Here there are three considerations:

* If it is the result of acquisitions or mergers of otherwise separate firms, there may well be a vital role for antitrust enforcement to prevent such transactions.

* If it is driven by an inherent underlying technology that gives rise to extensive “economies of scale,” then it is likely that only a small number of suppliers may be commercially viable.

* If market dominance is achieved through organic growth because of providing a wholly new product or service, then we are in the proverbial “grey area,” where careful, rigorous analysis needs to be carried out to make judgements. For all of the FAANGs, elements of each of these dimensions are present in one form or another. The case of Google provides a useful illustration.

Some might argue that Google’s pre-eminent position in today’s search engine market is the result of, say, Microsoft Edge’s inability to provide the same quality search results through Bing. Others would have it that Google is engaging in predatory practices to prevent Edge from gaining market share. Google’s present dominance certainly looks assured as far as the eye can see. It’s not as if Mozilla Foxfire and Duck Duck Go aren’t increasingly playing disrupter roles.

It’s also instructive to recall, that before Google, Microsoft’s precursor to Edge, internet Explorer, was the one-time dominant player. In those days, the rival search engine, Netscape, began to lose market share for a variety of reasons. While some of them were the result of poor business strategy decisions by Netscape, it also was tough to compete against Microsoft, which bundled internet Explorer within its core PC software — a practice that was the subject of a significant antitrust suit brought against Microsoft.

Assessing the competitive impacts of the FAANGs on the welfare of consumers and other businesses is no simple matter. A nuanced, systematic analysis, including one that takes into account dynamic changes in technology rather than a static snapshot, is called for.

While such firms may well engender economic and social costs, the benefits they provide are unquestionably substantial. Wisely, antitrust officials in the US are, to date, taking a clear-headed, inclusive and interdisciplinary approach in coming to judgements about them. Those in the EU and India — among others — would do well to do the same.

Harry G. Broadman is Managing Director and Chair of the Emerging Markets Practice at Berkeley Research Group llc and a faculty member of Johns Hopkins University.